timeStr = input()

#12:23:23

timeList = timeStr.split(":")

h =int(timeList[0])
m =int(timeList[1])
s =int(timeList[2])

s +=1

if s == 60:
    m +=1
    s = 0
    if m == 60:
        h += 1
        m = 0
        if h == 24:
           h = 0

print("%.2d:%.2d:%.2d" %(h,m,s))  #取两位小数  %.2d:%.2d:%.2d